Process and mechanism for separating intermixed divided materials



, 1931. K. DAvls PROCESS AND IECHANISII FOR SEPARATING INTERMIXEDDIVIDBD MATERIALS Aug. 4

Fl'led Dec. 3, 1925 5 Sheets-Sheet l IN VEN TOR.

Agg. 4, 1931. K. DAVIS 1,817,297

PROCESS AND 'MECHANISM FOR SEPARATING INTERMIXED DIVIDED MATERIALS FiledDec. 3, 1925 5 Sheets-Sheet 2 5/ i2 53 72 47 e r Z3 W @o 73 e/ 47 z Z fL l27 L29 'Z7 L27 e? 28 Y" 76 4 25 7 /H f ,52 //5 7 H5 v /52 104 M8 my lmy; i /09 ug. 4, 1931.l

' K. DAVISv PROCESS AND IIECHANISM FOR SEPARATING INTERMIXED DIVIDEDMATERIALS 5l Sheets-Sheet 3 I-l'edl Dec.- I5, 1925 R Y .E m ,N V f T. w.,A MVV B. I'.

u, mmv I K. DAVIS Aug. 4, 1931.

PROCESS AND HECHANISI FOR SEPARATING INTERMIXED DIVIDED MATERIALS medDec. 3,1925 5 sheets-sheet 4 INVENTOR lf' ORNEY Aug. 4, 192,1.V K. DAVIS1,817,297

PROCESS AND MECHANISM FOR SEPARATING INTERMIXD DIVIDED MATERIALS Filednec. 3,1925 s sneets-sheet 5 Patented Aug. 4, 1931 UNETED STATES PATENTOFFICE KENNETH DAVIS, OF EBENSBURG, PENNSYLVANIA, ASSIGNOR, BY MESNEASSIGN- MENTS, "EO PEALE-DAVIS COMPANY, F WILMINGTON, DELAWARE, ACOR-ORATIO'N or nELAvJaRE vPROCESS AND MECHANISM FOR SEPARATINGINTERMIXED DIVIDED MATERIALS Application filed December 3, 1925.

The invention is directed to a novel and useful process and mechanismfor separating intermiired divided materials of different specificgravities; and more particularly to a process and mechanism forseparating such materials which vary relatively greatly in the size ofthe intermixed fragments or particles, while on the other hand, varyingrelatively little in their specific gravities.

Objects and. advantages of the invention will be set forth in parthereinafter and in part will be obvious herefrom, or may be learned bypractice with the invention, the same being realized and attained bymeans of the instrumentalities and combinations Vpointed out in thnappended claims.

rlhe invention consists in the novel parts, constructions, arrangements,combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a parthereof, illustrate one embodiment of the invention, and

together with the description, serve to explain the principles of theinvention. Of the drawings vFig. 1 is aA side elevation of a mechanismembodying the invention, with the right-hand vend thereof broken away;Fig. 2 is a side elevation of the right-hand end of the mechanism shownin Fig. 1 and adjoins thereon, the two figures constituting a. completeside elevation g Fig. 3 is a horizontal section, taken on the 0 line 83of F 1, on a larger scale, and with the central part broken away; Y

Fig. 4 is a transverse, horizontal section taken on the line 4 4 of Fig.1;

Fig. is a vertical, longitudinal section talen on the line 5 5 of Fig.3;

Fig; (i is atop plan of the supporting frame ofthe table shown in Fig. 1with the pervious deck and superstructure removed Fig. 7 is afragmentary, vertical section on the line 7-7 of Fig. 6;

Fig. 8 is a fragmentary plan, partially diagrammatic, showing therelation of the air zoning and the separating partitions on the table; y

Serial No. 72,894.

Fig. 9 is a diagrammatic plan showing the present preferred form of airzoning;

Fig. 10 is an enlarged fragmentary section on line 10-10 of Fig. 3.

The invention comprises a process and mechanism or separating intermixeddivided materials, and delivering' the different separated materialsapart from each other and free from intermixture. The invention isdirected more particularly toproviding an improved process and mechanismwhereby intermixed materials are Successful] rated, wherein thefragments or par les of the various materials vary very greatly in size,and wherein the various intermi-ied materials differ relatively butlittle in their specific gravities; the rapid and successful commercialseparation thereof thus presenting a very difficult problem.

The expression intermixed divided materials is used foi,` convenienceherein in designating a mixture comprising two or more materials ingranular, fragmentary, pulverulent, or other like state, whether naturalor due to previous handling or operations. The expressions heavier andlighter as applied to the materials, pertain to relative specificgravities, and arc so used for convenience.

An example of materials, in the mechanical conditions and having thephysical properties already described. is a mixture of coal, bony, androck and other impurities, as it comes from the mine, and the presentinvention in actual practice has been chiefly directed to the automaticcleaning of the coal as it comes out of the mine.y and without pie viouspreparation or handling.

One of the principal and most valuable features of my process andmechanism is, the ability to practically completely separate coal, bonyand rock without theI preliminary sizing which has heretofore beennecessary, and which constitutes tremendous and practically prohibitiveitem of labor and expense. By my invention, l am enabled to practicallycomplete the separation of the coal, bony and rock, as it comes from themine, from the finest dust up to pieces three inches in dimensions, by asingle operation desired.

' According to previous commercial practice, except bythe cleaning'Vtables disclosed in and covered by certain of my copending applications,it has Vbeen necessary to very closely size the coal by preliminaryscreening before atteinptingthe automatic separation of the interiniziedcoal, bony and roclr;

As an example of necessary previous commercial screening preparatory toseparating All sizes above two inches were screened out; from two inchesto l and 1/2 inches were screened as the neil-tr site; then from 1%inches to l inch; from l inch to l/ inch; from 1/2 inch to l@ inch; fromlg inch i to 1S inch; from 1-/3 inch to -g inch; and from f@ inch downwere screened out on successive screens. Each of these sizes is thensent to a different separating table. rlhus seven or eight differentscreens are required and seven or eight separating tables, one for eachdifferent size of the intermixed materials praduced by screening, makingabout lfourteen or more machines and operations in all.

By my invention, l dispense with all of the screening mechanisms of theprior art and with all but one of the separating tables. l

Vpletely separatethe coal, roclr, and bony and use only a single largeseparating table.v

over this single table l send the unprepar lo., intermizied materials,which prior to my in# vention were necessarily sent first over theVseveral 'screening mechanisms, and then over thelcorrespendingseparating tables, as described in the precedingparagraphs. l am able on this one table to practically comotherimpurities from three inches in dimens sion down to the finest dust.. sy n' y AMy inventionis applied to the separation of a continuous andforwardly flowing bed of the intermiued, divided materials, such as theunsiZed mixture of coal, bony and roclr, the bed of materialsu'ndergoinpV parition being supported upon an air pervious table,throughrwhich a blast of air is driven from beneath upwardly through thebed of inaterial, the table at the same time beii noyed or reciprocate'dto mechanically forward th ing on the material at a locus which is atorY near the rear end of the separating table, and preferably entirelyacross this end, at such rate as to build up vat the beginning, and

`f 'thereafter to continuously maintain, upon the the separatedmaterials are delivered from the table. Y

By my present invention, the intermixed materials are fed on preferablyentirely across the rear end of theair pervious table,

and beginning at this time and continuing progressively forwardly alongthe table, the intermixed particles or fragments of material areloosened apart and separated from each other, and the lighterv materialgradually forms a flotant top stratum, and the heavier materialgradually settles and comes to rest upon the table, and thereafter isprogressed forwardly by the combined action of friction and inertia to aplace of delivery.

Broadly considered, in connection with the foregoing, the processandtable of my present invention, iny additionV to creating thissuperior liotant stratum of the lighter ma terial. provides also forthis stratum traveling forwardly in a straight and unconstrained gathand at the end of its straight and unconstrained path, to be deliveredfrom the table, thereby giving the shortest and most natural path to thesuperior liotant material. y

The heavier material which comes to rest upon the table, is acted. on byfriction and inertia, and is propelled to the side of the table as soonas possible, and then is 'progrossed in a continuous and uninixed streamforwardly along this one edge of the table to a place of'delivery,without interfering or intermixing with the straight and uninterruptedflow of the lighter superior flotant stratum. j ln connection with theforegoing, the air action is cooperatively proportioned and disposedtoproduce the .coinpletest and most satisfactory result in thediiiiculttask of completely, or practically complet-ely, separating the particlesof intermiXed material of such widely divergent dimensions and soclosely related in relative specific gravity. Accordingly, the area orzone of greatest air activity is at or near the place of feeding on ofthe intermiXed inaterials,and decreases substantially forwardly alongthe table, and also decreases transversely across the table in thedirectionvof movement of the lighter stratied materia-l, in conjunctionwith the forward disposition already described.

n The foregoing general description and the following detail descriptionare both er@ planatory and illustrative of the invention, but are notrestrictive thereof.

Referring now in detail to the present preferred embodiment, theseparatingtable is llU lle'

adapted to support and progress a bed of materials which is continuouslymaintained thereon of substantial thickness, the materials beinggradually stratified and separated by a single continuous operation. Asthe bed of materials moves slowly forwardly along the table, thelighter' and superior stratified material nieves in a stream forwardlyand longitudinally of the bed. The heavier and lower stratum of heavymaterial, immediately upon stratification and settling upon the bed, ismoved laterally to the sides of the bed and is thereby substantiallyseparated therefrom, and is then progressed forwardly by friction andinertia to discharge, and is discharged immediately from the sides ofthe bed almost as soon as separated. The feed of the intermiXedmaterials to the rear end of the bed is regulated to maintain the bedcontinuously of the desired thickness, which usually ranges from live tonine inches of the mixture of coal, rock and other impurities as itcomes from the mine.

The means for feeding on the intermixed, divided materials may be of anydesired or known form, adapted to feed the materials variably orregulably, at the desired rate, to the table. As embodied, a hopper l isprovided, having vertical side walls 4 and front and rear walls 2 and3which converge downwardly. A t the bottom of the hopper is a regulablefeeding device 5, shown as comprising a horizontally-disposedpartly-cylindrical casing 6. Mounted therein is a rotatable shaft 7,upon which is fixed a plurality of discs 8. Between the discs 8 arearranged a plurality of feeding blades 9, with their ends fixed to thediscs and in substantially7 tangential relation to the shaft 7.

The shaft 7 is rotated by any desired form of variable speed drive, andthe intermiXed materials are thus regulably fed out from the hopper lthrough the opening 10 onto the rear end (the right-hand end in Figs. land 3) of the table. The feed of-the materials is preferablysubstantially entirely across the rear end of the table.

The table comprises a fiat, air-pervious deck 28, of suitable material,the degree of perviosity in the different parts of the table beingvaried to edect the practically complete separation of the materials inthe bed as they pass over thetable. The perviosity of the deck changespreferably forwardly along the table and also outwardly from the centralpart toward the side edges, as with an intermixture of rock and coal andother nism is built upon and'carried by the upper part of the airpressure chamber, the table and air chamber reciprocating longitudinallytogether. In said embodied construction, the air chamber has side walls24 and Q5, a front wall 22, and a rear end wall 26. Fixed to the wallsof the air chamber, near the upper edges thereof, are angle framemembers 27 and Q8, extending entirely thercabout. Upon these framemembers 27 and 28 are supported a plurality of longitudinally-disposedframe members 29, the air-pervious deck 23 of the table being supportedupon the frame members 29.

Fixed to the side walls of the air chamber (Figs. 4 and 6) entirelyabout their bottom edges, are longitudinally-disposed angled framemembers 33, 84 and 35, which, together with the side walls of theair-chamber, rest upon correspondingly shaped frame channel bars 38, 39,and 4l, the frame thus being of the shape and size of the air-pressurechamber. The frame has preferably inner cross-bracing members 42 and 43.The air chamber as so constructed is carried upon resilient supports,and has a flexible conduit connection to the source of air pressuresupply, to permit longitudinal reciprocation of the table, as will belater more fully described.

Referring now to the embodied means for separating and stratifying theintermixed, divided materials upon the air pervious deck 23 of thetable, a plurality of spaced apart separating partitions 47 areprovided, lined to and extending upwarc ly from the face of the table. Trese partitions extend from substantially the central, longitudinal axisof the table, obliquely outwardly and forwardly, terminating somedistance from the side wall of the table to provide rock channel at theextreme side edge of the table. The separating partitions are arrangedpreferably in pairs, with their inner ends abutting at the centrallongitudinal abris of the table, the members of each pair diverfjingforwardly and outwardly from said central point of juncture, and arepreferably parallely arranged.

Across the rear end of the table is a wall 48 for the purpose ofretaining the bed of materials on the table, and the separatingpartitions at the rear end of the table, abut at their rear ends againstthis rear end wall 48, the arrangement in abutting pairs alreadydescribed beginning at the wall and extending forwardly therefrom alongthe table, as will be seen from Fig. 3. rilso for the purpose ofretaining the bed of materials upon the table, two side walls 49 and 50extend upwardly from the rear portion of the side edges of the table,and at their rear ends are connected respectively to the ends of therear wall 48. These walls 49 and 50 entend forwardly and outwardly alongthe edges of the table, terminating at the widest part of Lid theVtable, these `three, wallsv acting to retain the bed of materials uponthe rear part of the table. To retain the bed of materials upon theforward part of the table, and also to permit delivery of the forwardlytraveling superior stratum of coal or. other lighter material,upwardly-projecting side walls 5l and 52 connect with the forward endsof the kside walls 49 and 50, and extend forwardly titions mayoptionally decrease in height very gradually from their central point oflmncture outwardly toward their free ends.

The exterior ends of the separating partitions, as already indicated,terminate at seine distance from the side walls of the table leavingVfree passageways 5l and 55 along the side edges of the table aschannelways for the separated rock, or other hearier'inaterial, alongwhich said material is moved byv fric-v tion and inertia to discharge.The separating partitions, forwardly along the table, terminategradually farther and farther away from the lside walls, whereby theroel: channels are wider and wider forwardly along the table toaccommodate the greaterv volume of roc-lr or other heavier material asVthe separation ofthe intermixed materials progresses.

The intermixed divided materials, as will be understood from theforegoing description, yare preferably continuously fed, in the desiredvolume to maintain the bed upon the table, in what may be termed anarrow belt, substantially entirely across-the rear end of theseparating table, vvery close to and substantially parallel' with therear wall i8 of the table. rl`he separating action begins at this point,the materials becoming` immediately partially stratified, the heavier orlarger' pieces of roclr settling immediately uponthe table, and the mostof die lighter material possibly the smaller pieces of the heaviermaterial being floated or sustained at differont levels above th table.

llt the same time, Ythe -materials are imp forwardly along the tablewith the generaltravel of the bed, due in partfo the reciprocatorymotion of the tablerto be later described. f The roclr or other heaviermaterial, especially the larger pieces thereof, settle behind theseparating partitions and due to the motion Aof the table areimmediately impelled, friction vand inertia, to the sides of the'table,and'out of the body of the bed of materials, and are then impelledforwardly along the side edges of the table, practically separate andvapart from the stratifying bed, to their place of discharge. A littlefarther along the table, in like manner, the somewhat smaller pi-eces ofrock, or other heavier material, settle behind the separatingpartitions, and are immediately impelled sideways into the gutters orpassageways along the side edges vof the table.

rllhe coal, or other lighter material still remains notant above theseparating partitions and is impelled directly forwardly along thetable, in a direct and immediate path, to discharge at the front end ofthe table. This operation vrcontinues forwardly along the table as toboth materials, involving gradually the smaller and smaller pieces ofseparaed roch, all of the rock gradually settling behind the separatingpartitions and being iinpelled sidewise out of the bed and into thelongitudinal rock channels and is impelled forwardly to delivery. rlhesuperior ilotant stratum of coal is thus gradually and lfinallypurifiedl bythis single operation, and moves in a stream, as alreadyindicated, directly forwardly along the table above the separatingpartitions and in anon-obstructed stream toward the front end of thetable and` is discharged therefrom. Y Due to the forward narrm Tingofthe table, in the preferred illustratedv form, the side portions yof theforwardly moving stream of coal overflow the side edges of the table.`This provides a greater extent of discharging edge for the superiorflotant stratum of coal or other divided material,

which is an advantageous feature, in that it increases the capacity ofthe table.

lWhile all the separated roc-lr, or other heavier material, flowing inseparated f' streams along the side edges of the table, may bedischarged entirely at a single place at either side, near the forwardend of the table, it is found preferable to discharge the rockgraduallyv from the side edges of the table. By this arrangement ldecrease the volume of flowing rock, and also lessen the labor ofconveying it to discharge. For this purpose, as embodied, a plurality ofopenings are provided, at either forward side edge of the table, in theVbottom part ofthe side walls 5l and 52, and just at the level of thetable 23. These openings preferably increase in height forwardly, asbest shown in Fig. 5, to prevent the wedging and holding of piecesV ofroel; passing therethrough. 'l

To convey away the separated and discharged roclr, there is provided onthe outsideof each of t-he openings'GO, a short forwardly-extendingchute 6l, these chutes emptying into a lforwardly and downwardlyinclined chute (i2. rlhese chutes are conveniently constructed integralwith the coal conveying chutes later to be described, and are Supportedby brackets 78 and 79 from the respective side walls of the air pressurechamber.' These chutes discharge all the rock, or other heaviermaterial, upon a conveyor belt 68, transversely arranged at the yforwardend of the table. Each of the chutes 01 is preferably provided with aregulating gate 63, which may be set to control the volume of rockdischarged from the gate.

The embodied form of means for receiving and delivering the stratifiedand separated` superior layer of lighter material, such as the coal,comprises horizontally-disposed shelves 72 and 73, fixed to, andextending outwardly from, the upper edge of the side walls 51 and 52 ofthe table. Plust beneath the outer edges of the shelves 72 and 73,respectively, are located chutes 7 6 and 77, supported by brackets 78and 79, fastened to the exterior walls of the air pressure chamber. Thedischarged coal flows over the outer edges of the shelves 72 and 73, anddrops into the chutes 7G and 77. These chutes are forwardly anddownwardly inclined, and at their forward ends f 73 theyvdiseharge ontoan endless conveyor belt 81, arranged transverselyT along the forwardend of the table. Short forwardly and outwardly inclined walls 80 areprovided at the forward ends of the respective shelves 72 and 73 todirect any coal reaching those points into the corresponding chutes 7 6and 77 The main body of the separated and stratified coal, or lightermaterial, is discharged directly over the front end of the table, and

in the embodied form of means carrying out this function, vthe frontedge 88 of the table is unobstructed, and is provided with adownwardly-extending lip 89, discharging into the transversely-disposedconveyor belt 31. The separating partitions terminate at quite adistance from the forward end of the tabie, as `clearly shown in Fig. 3,and from this point forwardly the table itself is preferably solid, orimpervious to air, as indicated at 23a in Fig. 3.

. At either. side ofthe table, and just forwardly of the front pair ofseparating partitions 47, there are provided two outwardly and forwardlyinclined walls 91 and 92.

The upper inner edgesrthereof start from the level of the table, areinclined upwardly and outwardly, and at their outer ends aresubstantially level with the tops of the respective side walls 51 and52. The purpose of these two walls is to direct into the foremostopening for the discharge of therock any final fragments of the rock, orother heavier material, which may be resting upon the surface of thetable and be mov .ig forwardly, and to prevent these portions of rockfrom being discharged with the central, forwardly-moving stream of cleancoal or other lighter material. i

Means are provided by the invention for longitudinally reciprocating thetable, and

cooperating therewith, means for varying the inclination of the table.As shown herein, and in operating` most efficiently upon most kinds ofintermixed materials, the table is upwardly and forwardly inclined. Inthe embodied form said means. a foundation wall o1? concrete or othersuitable material is mounted upon any suitable base, and is of the samegeneral shape and size as the table itself. A frame 10i, preferably ofchannel beams is provided, which preferably of the same size and shapeas the frame 38%1, 'which supports the air pressure chamber. has beenalreffr. i described as being of substantially the shape and size of thetable.

The frame 104i mounted upon, and is vuriably inclinable relatively to,the supporting wall 103. For this purpose, the frame 104 at either sideand toward the rear end thereof, is provided with hinged or pivotal.mountings 107 and 10S, supported upon the top edge of the foundationwall 103. Near the forward edge of the sidev reaches of the frame 104are means for rocking the frame about its pivotal mountings 107 to varythe degree of inclination of the table. As embodied. cylindricalsupports 109 are mounted upon the top edge of the foundation 103.y andwithin the cylindrical members 109 are .screw posts 110, and nuts 111are screwed onto the posts and rest upon the top ednes of the respectivesupports 109. rlhe screw posts 110 have a ball and socket conneetion attheir top ends with members 112, which are iii-ted to, and extenddownwardly from, the l.ower.sides of the corresponding reaches of theframe 101i. Thus by turning the nuts 111 the inclination of the tablewill be varied. Se far'as concerns the broad features of the invention,the direction of inclination may be reversed, or may be in eitherdirection.

Referring now to the embodied form of mounting of the table forlongitudinal reciprocatory movement, and the means for effecting same,there are a plurality of resilient supports between the frame members104` and the frame members 38. These comprise a plurality of pairs ofangle pieces 116 and 117 'fn-:ed to.l and disposed transversely of, andin spaced-apart relation along the tops of the side members of the frame10,4. A plurality of pairs of corresponding similar angle pieces 113 and119 are fixed, in like spaced npart relation, 'to the nndersides of thecorresponding' 'de frame members 38 and 3S, which are fixed to thebottom of the air-pressure chamber. Riveted to each of these pairs ofangle pieces is a vertically disposed, flexible supporting member 115,these members supporting the air chamber and table, and flexing duringthe actuation of the table to provide the necessary longitudinalreciprocatory movement.

The embodied form of means for recipro frame 104. edges making air-tightconnection with the lower part of the reciprocable frame 38E-'11, .thusmaking an air-tight connection which eating the table comprises a rod125, pivotally connected at 126 to the center of the rear end of thetable. This rod, at its rear end 127, is pivotally connected to a crankdisc 128, lixed on-a shaft which is journaled in bearings 129, mountedon the top of the foundation 103. Fixed also to this shaft is a gearwheel 130, with which meshes a pinion 131, ixed on a shaft Y132, whichshaft is journaled in bearings 133, likewise mounted on the top of thefoundation wall r103. Fixed also to the shaft 132 is a belt pulley 134,over which runs a belt 135,'this belt running also over a pulley 136,Vfixed on the shaft of a motor 137. 1t will be understood vthat anysuitable or known form of Y reciprocating mechanism may` be used,so faras concerns most features of the invention.

The embodied form of means for supplying air pressure comprises ablowing fan 145, which blows the air into a conduit 146, which conduitextends longitudinally and centrally within the foundation 103. The topface of this longitudinally-extending conduit 146 is open substantiallyfor the entire length of the air-pervious part of the table 23, andairtight connection is made along the edges of the open top of theconduit by the bottom edges of a similarly shaped impervious flexibleenvelope 148, of canvas or other suitable material, this `envelopeextending upwardly therefrom. .rt its upper end, the top edges of theenvelope 148 are connected air-tight to the lower part of the tiltablebut non-reciprocating frame 104. By this connection the framel 104.V maybe tilted or variably inclined, with reference to the stationary7conduit 146 as already described.

To permit the reciprocatory movement of the table and lair pressurechamber,a similari -slia ved flexible envelo Je 152 has its l a loweredges fastened air-tight to the u `ver part. of the tiltabie butnon-reciprocating rlhis envelope 152 has its upper willv permit thereciprocation of the table and air-chamber.

Thus the table is longitudinally reciprocated and is supplied .with airunder pressure. The amount or intensity of the air currents through thebed of materials being separted on the table may bev entirely' reguflated by the degree of perviosity of the table or decl; 23, asalready'described. lf desired, however, balile plates or shuttersl maybe provided within the air chamber, or within thev my co-pendingapplicationSer. No. 716,322,

filed May 28, 1924.

" Resilient means are provided, cooperating withthe table-reciprocatingmeans, already described, to prevent shock and racking during thereciprocation of the table, and devices are also provided for regulatingthis resilient action. 11sv embodied, a rod llis fixed-to thereciprocable table andair chamber frame 38-41, being screv/J-threadedinto a bracket- 162, i rhich is bolted at 103 to the reciprocable frame,and is heldin place by a pinned collar 104. The rod 161 is reciprocableinan apr-.rtured bracket 105, which is'bolted at 166 to the tiltable butnon-vibratable frame 104. A spring 157 is coiled about rod 161, and isin compression'between the bracket 165 and a tension-regulating loch nut16S, screwthreaded on the rod 151, thereby giving a regulablespring-'action to the vibration of the table. f V

Suitable means are preferably provided.

for collecting the dust created by the separating action upon the table,and this means .may be the saine as, or generally similar to,

that shown in my copending application Ser. No. 612,450 filed Jan. 13,1923. As embodied, a casing 171 is mountedvabove the table, and aiiez-:ible shirt 172'is fixed to the lower edge th reof and extendsdownwardly about the ta the ascending air current carrying the o1 st upinto the collecting and settiing` mechanism above. etti the forward endof the table (F 1), the dust collector terminates snort of the front endof the table, and the shirt 172 thereof comes down on the bed ofmaterials some distance from thev front of the table, leavingthefrontend of the table accessible for'inspeetion.

The relative degree ofair current forced through the bed of materials isvaried in dif-v ferent parts of the-air pervious table, so as tosecurethe best and most efficient separating action, and especiallytosecure this result with a table of the particular struct-ure, andhaving the/.separating partitions arranged in the manner, of myV presentinvention. vThis may be accomplished by varying the degree of airperviosity indifferent parts vof the table. y -x f ln accordance withone feature of my inventionn tberelative disposition of the variousareas of different air perviosity, and the relation thereof to thedifferent parts'of the table', to the direction of travell of theheavier and lighter separated materialaiand to the separatingpartiticns,is represented-more or less diagrammatically in Figs. 8 and 9of thev drawings. lThe arrangement of the various areas of differentyair perviosity is shown in Fig. 9, and the arrangement of the separat-VYing partitions is shown in Fig. 8.

ln Fig. 9 the areas of different air perviosity are indicatedrespectively by the letters a, Z9, o, CZ- and e, the letterarepresenting the l area of greatest air perviosityand theletter erepresenting the areaof least air perviosity.`- While these differencesnr air perviosity, and

loo

consequent difference in the force of the air currents, are representedas definite areas, it will be understood that they can blend from oneinto the ther in so'far as concerns the principal features of theinvention, although structurally it will he found advantageous to securethe desiree effects by making the deck of the table of metal plateshaving perforations therein varying in size or in number for a givenunit area.y l

F rom a comparison. of Figs. 8 and 9, it will be seen that the degree ofair perviosity of the table, and therefore of the force of the ircurrents therethrough, for the greater part of the table, increasesoutwardly and forwardly along the separating partitions, that is, withthe transverse outward flow of the rock from the center of the tabletoward the edges, the greatest air perviosity and therefore thestrongest air currents being along the outer edges of the table at theplaces of discharge of the rock. It will be noted further that thegeneral disposition of the various areas of equal air perviosity isforwardly along the table, that is, in the general direction of the flowof the superior stratum of separated coal or other lighter ma terial.

ln F S also the present preferred arrangement of separating partitionsof varying height is shown. this arrangement,

`anj,v7 particular separating partition is pref erably of uniform heightthroughout, but the heights of the separating partitions decreasegradually .forwardly along the table. In Fig.

8 there are shown four groups of separating partitions, denoted by theletters A, B, C and D, disposed lo dinally of the table, the separatingparti -ions A at the rear of the table being of the greatest height, thegroup B of somewhat lessery height, the group C being of still lesserheight, and the group D of least height. It will be noted thus that theseparating partitions decrease in height longitudinallj,v7 of the table,that is, in the direction of travel of the coal or other lightermaterial being separated.

Means are provided by the mechanism just described for regulating therate of discharge and therewith the depth of the bed cr stream ofheavier material flowing, or rather sliding hy friction and inertiaalong the channels 54 and For this purpose, the gates G3 are madevariably positionable as shown in Fig. l0, and this may be done by anysuitable means` shown, a springpressed notched pivoted bar attached toeach gate G3 and projects downwardly through a small openin the bottomof chute 6l, one of the notches or teeth resting upon the top edge ofthe opening. Thus the depth of the bed or stream or rock or otherheavier material just within the opening 60, and backwa rdly along therock channel may be regulated as desired. The openings 60 may also beregulated and varied in size a further cooperating or as an alternativeregulation of the depth of the bed of roel: or other heavier material.As shown a sliding gate 60a mounted above the opening 60 and is held inregulated position by holt and slot connection 60 with the side wall 52of the table.

From all the foregoing it will be understood that a mechanism has beenprovided constituting an exemplary embodiment of the invention, andrealizing the objects and advantages herein set forth, together withother objects and advantages. It will be understood further thatdepartures may be made from the exact mechanism as shown and described,within the scope of the accompanying claims, without departing from theprinciples of the invention and without sacrilicing its chiefadvantages.

lVhat l claim is l. A mechanism for separating intermixed dividedmaterials varying relatively greatly 'n size and relatively little inspecific gravity, such as unsized coal, including in combination arelatively long and narrow air-pervi'ous table having separatingpartitions disposed forwardly and transversely thereon, means for recirirocating the table longitudinally, discharge devices adjacent theforward ends of the separating partitions for delivering heaviermaterial from the table as soon as it reaches the ends of the separatingpartitions, said separating partitions decreasing in height graduallyand progressively from the rear toward the front end of the table` andthe air-perviosity of the table also decreasing gradually, progressivelyand continuously from the rear toward the front of the table.

2. In a mechanism for separating intermiXed divided materials, a devicefor controlling discharge of heavier material from an air pervious tableincluding in combination a retaining wall along an edge of theair-pervious table, separating partitions for directing heavier materialtoward said wall, an opening in the wall extending upwardly from thetable surface for permitting escape of heavier material directed theretoby the separating partitions, and means for controlling the amount ofheavier material discharged through the opening comprising a surface inthe path of the heavier material inclined upwardly from the plane of thetable and means for varying the inclination of said surface with respectto the table to control the gravital opposition to the escape of saidheavier material.

3. In a mechanism for separating intermiXed divided materials, a devicefor controlling discharge of heavier material from an air-pervious tableincluding in combination a retaining wall along an edge of theair-pervious table` separating partitions for directing heavier materialtoward said wall,

CLI

an opening'in the Wall extending upwardly from the table surface forpermitting escape lof heavier material directed thereto by theseparating partitions, and means for 4controliing the amount of heaviermaterial discharged through the opening comprising a member for varyingthe size of the opening, asurace in thepath of the heavier materialinclined upwardly from the plane of the tableV y and means Jfor varyingthe inclination of said surface'vvith respect to the table to controlthe gravital opposition to the escape of said heavier material.

, l. A mechanism for separating intermixed divided material including inco1nbination a longitudinally reciprocable, air-pervious table Whichdecreases in Width fforwardly, meansy for feeding said material totlierear end thereof, `material-retaining Walls along the side edges ofthe table for maintaining thereon a bedv of materials of substantialdepth, separating partitions disposed vforwardly and outwardly alongthetable for guiding settled heavier material transversely in aplurality of streams, means 1for discharge ing said streams along a sideedge of the table through openings in the retaining Walls, and means fordischarging flotantlighter material at the front end of the table andover one of the side Walls near the Jfront end of the table, and meansfor maintaining `the discharging lighter material above and separatedfrom the discharging streamsof heavier ma erial. y

In testimonyivhereo, I have signed my name tothis specification. Y

KENNETH Davis.

